Turbine-driven rotary cutters and drillers are used in a variety of medical applications.
For example, U.S. Patent Application Publication 2013/0266430, whose disclosure is incorporated herein by reference, describes an air turbine handpiece having: a head portion with built-in free turbine blade, a neck portion installed consecutively with the head portion and grasped by an operator, a grip portion installed consecutively with the neck portion, an air supply duct for driving the turbine blade, and an exhaust duct for exhausting the air. The exhaust duct is provided with a reflux duct, open at one end to the exhaust duct, and open at the other end to the turbine room as the exhaust exit, a value in which an aperture at the reflux exit of the reflux duct is divided by an aperture in the air supply port of the air supply duct, becomes one or less, and the reflux exit of the reflux duct is opened to the turbine room near the air supply port between the air supply port and the exhaust exit.
U.S. Pat. No. 8,562,343, whose disclosure is incorporated herein by reference, describes a dental handpiece that uses a single airflow input to drive both a rotor and provide a hydrostatic bearing. The fluid flow in the form of compressed air is applied first to the hydrostatic bearings and then subsequently to the turbine blades of the rotor without the use of any moving mechanical parts by the design of the air passageway being more direct for the hydrostatic bearing. This passageway is the form of a manifold insert which may be mounted within the handpiece. The handpiece includes a pair of frusto-conical cages separated by a C-shaped spacer which enables precise fabrication. The frusto-conical ends of the rotor and the mating frusto-conical inner surfaces of the cages are provided with a diamond like carbon coating.
Documents incorporated by reference in the present patent application are to be considered an integral part of the application except that, to the extent that any terms are defined in these incorporated documents in a manner that conflicts with definitions made explicitly or implicitly in the present specification, only the definitions in the present specification should be considered.